1. Technical Field
The present invention relates to a method and system for controlling semiconductor manufacturing apparatuses, and particularly to a technique to reduce energy loss when the semiconductor manufacturing apparatuses are in a wait mode, without interfering with turnaround-time (TAT) reduction.
2. Related Art
A production line of semiconductor devices has a clean room that makes filtered clean air flow down and various manufacturing apparatuses arranged in the clean room. Examples of the apparatuses are: a thermal treatment apparatus that generates thermal diffusion of an impurity in a semiconductor wafer, a chemical-vapor deposition (CVD) apparatus that provides an insulating film, and a dry etching apparatus that etches an insulating film or a conductive film. Most of the apparatuses require not only electric power but also other energy such as evacuated air, cooling water, compresses air, vacuum, nitrogen (N2), and released heat.
In related techniques, when the manufacturing apparatus is set in a wait mode between product processes, power supply from a radio-frequency (RF) power source and a magnetic power source is turned off to reduce the output of a heater to some extent so as to cut down on the energy use. The manufacturing apparatus stays in the wait mode at a level at which product processing is ready to start (i.e., a processable level) as soon as a product to be processed is provided to a loader of the manufacturing apparatus so as not to interfere with reduction in turnaround time (TAT).
JP-A-2000-260672 discloses another method to reduce power consumption that uses a manufacturing apparatus (e.g. a coaster developer) having a plurality of units to conduct different processes on a semiconductor wafer. The apparatus does not supply electric power to the units in the waiting mode.
JP-A-5-77144 is another example of the related art.
In general, a production line handles not one type of product but multiple types of products in small lots. Different product types require different product processes. Accordingly, some manufacturing apparatuses in a production line are frequently used, and others are not. Furthermore, the frequency of the use of manufacturing apparatuses generally varies depending on the product type, volume, and process timing on a production line.
Therefore, it is rare to keep the manufacturing apparatuses in non-stop operation between predetermined maintenance breaks. In many cases, the apparatuses are kept in the wait mode between processes. The waiting time between the processes may last only for several minutes, or it may last for as long as a couple of days.
However, in the related techniques, the manufacturing apparatuses making up a production line are each in a constant wait mode at a level at which the apparatus is ready to start the product processing regardless of the length of time to wait for the next product processing. Therefore, if the waiting time is long, there is a large loss of energy.